1. Field of the Invention
The present invention relates to a method of forming a printing sleeve wherein at least one sheet of a thermoplastic elastomeric composition which is hardenable under the influence of light (a photopolymer) is applied upon a surface formed by a cylinder, a gas-permeable means being provided at the cylinder surface which extends at least along the entire inside and full width of the sheet applied upon the cylinder surface, and wherein the sheet is pressed against the cylinder surface with the aid of a decreased gas pressure so that, by applying the pressure in conjunction with heat, the sheet is secured to the cylinder.
2. Description of the Prior Art
A few of such methods have already been used in the art. For example U.S. Pat. No. 4,381,961, issued on May 3, 1983 to Hendricus J. van der VELDEN (assignee: STORK SCREENS B.V.), describes the use of a cylindrical core whose outer surface is provided with channels extending from one to the other end face of the cylinder, and as a result of which a gas inclusion is prevented from occurring. In another method, instead of a metal cylinder an inflatable core is used which forms a temporary support for a thin-walled metal sleeve to which the photopolymer sheet is secured. (see my U.S. Pat. No. 4,391,898, issued on July 5, 1983)
The present invention departs from the known method first mentioned herein which in practice has the drawback, however, that the core provided with the channels cannot be utilized as a carrier for sheet-shaped printing plates which are smaller than the full circumference and/or the full length of the cylinder. So far, the printing plates have been secured to the surface by means of double-face adhesive tape but the grooved cylinder surface precluded effective adhesion of the adhesive tape. This rules out the universal usefulness of such serrated roller cores.